Wilhelm Schickard

Biography

Wilhelm Schickard was born in Herrenberg on 22 April 1592. He attended the Lateinschule in Herrenberg, the monastery school in Bebenhausen, and the Evangelische Stift in Tübingen (a seminary for training students for priesthood) – the then usual education of a theologian. In 1614, at the age of 22, he was appointed deacon in Nürtingen.

Apart from his clerical duties he studied old languages, astronomy, and mathematics. In 1617, Schickard met Johannes Kepler who taught in Linz and was 20 years his senior. They became friends; Kepler praised Schickard’s scientific and practical skills, calling him an “ambidextrous philosopher”.

In 1623, decades before Pascal and Leibniz, Schickard invented a mechanical computing device which was capable of adding and subtracting numbers. Its distinctive feature was the automatic tens-carry mechanism. Multiplying and dividing, however, required user intervention. For multiplication e.g., the user had to determine the subproducts using Neper’s rods, and enter these into the six-digit adding mechanism.

The only model ever completed was lost in the upheaval of the Thirty Year War. A second version for calculating the complex movements of the planets, which Schickard commissioned for his friend Johannes Kepler, was destroyed in a fire. Based on drawings and descriptions left by Schickard and Kepler, the Tübingen Professor B. V. Freytag Löringhoff reconstructed Schickard’s “calculator clock” between 1957 and 1960, proving that it actually worked.

During the Thirty Year War, the imperial troops brought the pest to Tübingen and Herrenberg. The plague took first Wilhelm Schickard’s wife and three of his daughters, and on 24 October 1635, Schickard himself, at only 43, and his nine-year-old son.

More information

For a demonstration of Schickard’s computing device click here.